As a large projection display, there is known a multiprojection display system that projects images onto a screen from a plurality of projectors, and connects the projected images to form one screen.
In such a multiprojection display system, positional accuracy of the images projected from the plurality of projectors on the screen greatly affects quality of the entire projected images.
For example, when the projected images shift in position, a discontinuous joint may be formed between the images projected onto the screen or edges of the adjacent images may overlap each other, thus causing great deterioration of display quality.
To deal with the problem, for example, Patent Literature 1 discusses a method of detecting coordinate positions of marks by capturing images of a plurality of marks formed around a screen or a plurality of marks projected onto the screen, and adjusting positions of projected images based on the detected positions of the marks.
However, the multiprojection display system of the background art is configured to detect a boundary in the projection region for each projector by using the marks formed on an outer circumference of the screen.
The multiprojection display system of the background art can be applied when two projectors project images onto the screen to form one screen. However, the multiprojection display system cannot be applied when three or more projectors project images onto the screen to form one screen.
For example, when four projectors project images onto the screen to form one screen, the projected images are divided into four to be displayed on the screen, and hence a mark must be formed on the screen center to indicate the boundary in the projection region for each projector.
In the multiprojection display system of the background art, there is no mention of the marks formed on the screen or a using method thereof. Thus, the boundary between the projected images on the screen cannot be accurately identified, and a discontinuous joint may be formed between the images projected onto the screen or edges of the adjacent images may overlap each other, thus causing great deterioration of display quality.